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Peter MacNicholl February 24, 2003 Page 2 4. The amount and number of extraction well pumps that are out of operation (14) seems excessive for this age and type of system. I did not review the ROD to check the plume capture performance standard that the Tracy site is required to achieve, however, the regulators should consider development and use of an enforceable schedule to correct system operational failures and to ensure plume capture is achieved and maintained. 5. Attached is a generic spread sheet that can be used to present the generalized extent of hydraulic capture for specific groundwater extraction wells. It would be helpful if this type of information were included in future annual reports. DTSC believes it would be helpful for supporting plume capture evaluations or identifying potential gaps. Also attached is a copy of the U.S. EPA factsheet on elements for effective management of pump & treat systems that may be helpful when preparing future reports. Specific Comments: 1. Pages 2-10 through 2-17, Table 2.4-1. Screen depths are provided only in feet below ground surface and make it difficult to quickly compare and assess nearby screen intervals and relative position to extraction well screen intervals. To aid review of the information, screen intervals for all wells should be provided in depth mean sea level. 2. Table 2.4-1. Include a column to identify the sampling method (e.g. conventional pump, bailer, low-flow, etc.) by well. If all wells are sampled using the same method, simply put in a footnote in the Table that identifies the sampling method being used. If low-flow sampling or passive diffusion bag samplers are used, Table 2.4-1 should include the low-flow inlet depth or mid-bag depth. 3. Page 2-7, Section 2.4.5. Provide the vertical gradient values (e.g. 0.002 ft/ft) in the text as was done for the horizontal gradient discussion. 4. Page 2-27, Figure 2.4-1. Since there is a recommendation to temporarily shut down EW014A through EW017A, DTSC recommends including a North-South cross-section (along Banta Road) from EW014A through LM165A. 5. Page 3-1, Section 3.2. I'm not surprised the Mann-Kendall test (Table 3.2-1) did not identify a significant upward TCE trend for LM146A, but the time series review should have caught the upward trend. I would consider this a relatively important well considering that the 2002 Annual recommendation is to shut off nearby extraction wells.